I’m certain by now many of our readers have come across news of the current pertussis, aka whooping cough, epidemic in California. Beginning this February and accelerating dramatically through May and June, California has so far seen a ~500% increase in pertussis cases compared to last year, and only two days ago announced the death of a sixth baby from infection. Public health officials in California are currently working to control its spread and determine the factors that allowed this outbreak to occur, unfortunately, at this time the available data is very rough.
The number of confirmed cases as of 6/30/2010 is growing rapidly (1,377), with an additional ~700 cases pending investigation. General geographic location, ages, and ethnicity have been identified, and general vaccination rates and exemption rates are known, but other important demographic and epidemiologic data, including vaccination status of infected children and adults, has yet to be fully described. Lack of data notwithstanding, I have read equally hasty stories and comments blaming the outbreak on vaccine refusal, a large immigrant population, an inadequate adult vaccination program, and normal cyclical variation in pertussis incidence, among other factors. Finding where the system has broken down enough to allow this resurgence is exceedingly important, but in this situation pointing fingers is not as important as taking action. (more…)